An important requirement when seeking to reduce the size and weight, and also to increase operability, of a mobile radio communications device, relates to the power requirements of a device. If power requirements can be reduced then the useful lifetime of the device can be increased and/or the size of the device can likewise be reduced.
Recent attempts to reduce the power consumption within mobile radio communication devices have tended to employ the concept of discontinuous reception which generally allows for the device to remain active, but in a sleep or idle mode, and not requiring full access to the network nor the reception of signals therefrom.
Such discontinuous reception is known in Global System for Mobile Communications (GSM) devices and also in Universal Mobile Telecommunications System (UMTS) systems and which allows for the device to save power when in an idle mode since the device is not then required to continuously to receive downlink channels from the network.
Recent developments for mobile radio communication devices have included the provision of broadcast services such as Multimedia Broadcast Multicast Services (MBMS) which allow for the provision of specifically tailored information, i.e. news information and/or sport information, to be broadcast to a predetermined number of mobile communication devices, i.e. generally any such devices owned by users who have subscribed to a particular broadcast service.
For MBMS enabled devices, it is required that a notification channel to be employed by the broadcast service be read continuingly within the mobile device so as to achieve appropriate functionality.
Such functionality requires that the mobile communications device be informed when the MBMS sessions are to commence, and so that the device can be informed of the MBMS channel type, for example whether the channel type comprises a point-to-point channel type or whether it comprises a point-to-multipoint channel type. Also, the mobile communications device can learn from data on the notification channel whether the network needs counting such that, if counting is required, each mobile communications device subscribing to the service can declare itself to the cell of the devices that are to receive the MBMS session and the cell can then determine which channel to employ.
As will be appreciated from the above, current operation of a MBMS arrangement requires monitoring of the notification channel in order to receive the information available and such continuous monitoring of the notification channel disadvantageously increases the power consumption required at the mobile radio communications device even when the actual MBMS transmission is arranged to take place later. Thus, in view of such continuous monitoring, it is currently not viable for MBMS enabled devices to enter into a power-saving mode such as the discontinuous reception (DRX) arrangement noted above.